Yes of course they would stop any DC saying hallo to your LF driver should the amplifier decide that it has had enough.
'
The original purpose though was indeed to 'add' extended bass' to the design.
This trick was also used in the big tall subwoofer designed also as a stand for the LS35a.
Cannot remember who made the thing, age is taking it's toll as is the Cabernet!

What do you think would happen if I dumped them? I'm not particularly worried about my amp doing something bad.

Should I be in your area some time, I would be happy to give you a bottle of my Cabernet. Some of my older vintages that go back 20 years or so are drinking very well, and though I can't guarantee they will restore the little grey cells, as someone once put it, you won't mind as much.